(See related stories) (ANSA) - Milan, December 16 - The Italian government is ready to make mafia prison conditions even tougher if mob bosses continue to make threats or otherwise try to do business from behind bars, Interior Minister Angelo Alfano said Monday. "The bosses should know that if they try to send information or give orders from prison, the State will not be shy to prevent it and is ready to make tougher rules," concerning mafia prisoners, Alfano said during an appearance before parliament's anti-mafia commission. The government's 41-bis law covers Italy's most dangerous criminals and can keep them imprisoned in single-person maximum security cells, almost entirely cut off from the world to prevent further criminal activity. Earlier, Alfano said that four Italian magistrates have been put under the "highest level" of police protection after threats concerning their investigations of the Cosa Nostra Mafia. The increased protection was necessary after incidents of intimidation against the magistrates, said Alfano, who spoke only a month after former Cosa Nostra Mafia "boss of bosses" Toto' Riina issued further threats against Palermo deputy prosecutor Nino Di Matteo from prison.